Common catalyst price patterns

Biotech catalysts produce a handful of recurring price patterns. None are guarantees — they're tendencies driven by expectations, positioning and cash needs. These are the ones worth recognizing.

The run-up (anticipation pump)

Ahead of a known date — a PDUFA decision or a Phase 3 readout — speculators pile in and the stock drifts higher on rising volume. The move reflects expectation, not new information, and a steep run-up raises the bar the actual result must clear.

Sell the news (the fade)

When the event lands — even positively — early buyers take profits and the stock fades. The bigger the run-up, the more is already priced in, and the harder the fade. (See the dedicated guide.)

Gap-and-go vs. gap-and-fade

A binary readout gaps the stock overnight. Sometimes momentum continues for days (gap-and-go); sometimes the open is the high and it reverses (gap-and-fade) because the move was overdone.

The dilution dump

Cash-hungry biotechs often use a spike — a good readout or a run-up — to launch an offering (a 424B5 takedown or a PIPE). Fresh shares sold at a discount knock the price down. A short-runway company spiking on news is a prime candidate.

The short squeeze

A heavily shorted name (high days-to-cover) can spike violently on good news as trapped shorts buy to cover, amplifying the move beyond what the news alone justifies.

Capitulation & bounce (CRL or miss)

A rejection (CRL) or a failed endpoint can trigger a sharp, high-volume drop. Severe selling sometimes overshoots into an oversold bounce — but the underlying story is usually impaired.

The de-risking re-rate

Strong interim or Phase 2 data 'de-risks' a program; instead of fading, the stock can re-rate higher and grind up into the next milestone.

Sympathy moves

A readout can move peers that share the same drug mechanism or target indication — a competitor's win or failure spills over onto similar names.

Reverse-split death spiral

Chronic dilution drives the price toward $1; the company reverse-splits to stay listed, then dilutes again. The cycle repeats and grinds shareholders toward zero.

How our signals map to these

• Setup score → catches the run-up before an event.
• Days-to-cover → flags squeeze fuel.
• Dilution history + runway → flag the dump / death-spiral risk.
• Remember: patterns are probabilities, not certainties. Size and manage risk accordingly.